Antony Hewish

Hewish, Antony (1924-) is a British astronomer and astrophysicist, a scientist who studies the physical nature, origin, and development of the solar system, galaxies, and the universe. Hewish won the 1974 Nobel Prize in physics for his discovery of pulsars. He shared the prize with British astrophysicist Martin Ryle, who was recognized for his use of small radio telescopes to “see” into space with great accuracy. Their 1974 prize was the first Nobel Prize in physics to be awarded for astronomical observations.

Hewish was born in Fowey, Cornwall, England. He attended King's College in Taunton, where he developed an early interest in physics. Hewish entered Cambridge University in 1942.

Hewish's education was interrupted by World War II(1939–1945). From 1943 to 1946, he worked for the British government on anti-radar-detection devices for Allied aircraft.

Hewish worked at the Royal Aircraft Establishment in Farnborough and at the Telecommunications Research Establishment in Malvern, where he met Ryle.

Hewish returned to his studies at Cambridge in 1946, after the war. He received a bachelor's degree in 1948 and a doctorate in 1952. Hewish spent his entire professional career at institutions that are part of Cambridge University. From 1948 to 1952, he was a member of Ryle's research team at the Cavendish Laboratory. Hewish was a research fellow at Gonville and Caius College from 1952 to 1954 and then assistant director of research until 1962. He then transferred to Churchill College, where he served as university lecturer from 1962 to 1969, reader from 1969 to 1971, and professor of radio astronomy from 1971 until his retirement in 1989, Since 1989, he has been a professor emeritus.

At the Cavendish Laboratory, Hewish became particularly interested in the new field of radio astronomy, the branch of astronomy that uses radio waves to detect objects in space. He began to study the scintillation —twinkling—of radio stars, which are powerful masses of energy in space that emit radio waves rather than light waves. He used this scintillation to measure the height and dimensions of plasma clouds, collections of charged particles in the layer of the earth's upper atmosphere called the ionosphere.

Hewish used similar research to study radio waves that came from quasars. A quasar (a shortened form of the term quasi-stellar radio source) is an extremely bright object at the center of a distant galaxy. Hewish was able to show that when radio waves from a source with a small diameter, such as a quasar, travel through the ionosphere, the waves are diffracted, or scattered. This diffraction causes the appearance of twinkling in radio stars, an effect called interplanetary scintillation (IPS).

Hewish's work on IPS led to his discovery of pulsars. Pulsars are objects in space that emit regular bursts of electromagnetic radiation, which are received on the earth. Most of this radiation is in the form of radio waves. Hewish designed a large radio telescope with more than 2,000 individual antenna poles to receive radio signals from distant galaxies across a wide stretch of sky. The telescope was completed in 1967, and Hewish led a research team to observe the scintillations of stars. A graduate student on the team, Jocelyn Bell (later Jocelyn Bell Burnell), detected radio waves from an unknown source. Hewish proved that these signals were not caused by interference from earth nor by intelligent life forms elsewhere in the universe, but by the objects that became known as pulsars.

Hewish and his research team published their findings in 1968. They suggested that pulsars might be white dwarf stars or rapidly spinning neutron stars. White dwarf stars are hot, dense cores of dying stars. Neutron stars are dense stars composed primarily of tightly packed neutrons or perhaps of elementary particles called quarks. Other researchers soon supported the idea that pulsars are neutron stars. By 1998, astronomers had located more than 1,000 pulsars.

In 1946, Hewish was elected to the Royal Society. He later received the society's Hughes Medal. Other awards include the Hamilton Prize from Cambridge in 1952, the Eddington Medal from the Royal Astronomical Society in 1969, and the Dellinger Medal from the International Union of Radio Science in 1972. Hewish lives in Cambridge.